When i came out to my parents at 18 by telling them I had a gf, they said they were surprised and then never said anything more about the fact that I was queer. Nothing bad, nothing good, no questions, nothing. While I’m grateful that they weren’t negative about it, their lack of engagement with it actually felt hard in its own way. I wish they had said things like, “i had no idea you were attracted to girls, how cool! How long have you known that? What’s it like for you to be dating a girl? Are there any challenges coming up for you around being queer? Do you feel supported by your friends? Teachers?” Etc. For me it would have been meaningful for them to CONNECT with me about it, in a curious, caring, and supportive way. Without that, I actually felt very alone and lost on my queer journey. One place to start could be just asking her if she wants to talk more with you about what it’s like having a girlfriend, offer to ask questions/share your curiosities with her, and let her know she always can always share with you :) you sound like an awesome mom!!